A natural history notebook and project of the Missouri Botanical Garden

Grassland

This post is contributed by Dr. James Aronson, a restoration ecologist at MBG’s Center for Conservation and Sustainable Development, and his son Thibaud Aronson. James is also a researcher with the CNRS (National Center for Scientific Research) in Montpellier, France.

In Sinhalese Sri Lanka means “Resplendent Isle”, a fine name indeed for this tear-shaped island off the coast of southeastern India, just north of the equator. Last month I travelled with my son on a self-guided Natural History + Ecological Restoration visit, we are finding and photographing cloud forests and birds galore, like the endangered endemic Sri Lanka whistling thrush, Myophonus blighi, and the Kashmir flycatcher, Ficedula subrubra, which over-winters exclusively in the Sri Lanka highlands, from its very restricted breeding grounds in Kashmir, northern India.

We were also looking at the mosaic of grasslands, cloud forests, and lowland forests we find here from a restoration ecology perspective. That means we’re trying to “read” the landscapes we see in terms of known transformations carried out during the British colonial era (1815 and 1948, when Sri Lanka was known as Ceylon), and since independence. The remarkable Horton Plains National Park is a mosaic of montane grassland (ca. 35%) and cloud forest (ca. 65%), encompassing the headwaters of three major rivers. It was declared a sanctuary in 1969 and elevated to national park status in 1988; it became part of a large UNESCO World Heritage site in 2010. In the central highlands of Madagascar, grasslands appear to occupy about 99% and most people assume they are anthropogenic…. This month, I’m travelling with Leighton Reid in the Central Highlands of Madagascar, and we will be blogging about this soon.

Horton Plains National Park, where the grassland – cloud forest mosaic shows some sharp edges where human land use has had impacts, but otherwise with high species diversity and landscape scale heterogeneity.

Tree ferns (Cyathea sp.) in the Horton Plains cloud forest.

But, the history of preservation in the highlands here goes back a lot further, to the days when the Isle was part of the British empire, along with all of India. According to information we gathered at the extraordinary, and poorly known Hakgala Botanic Gardens, the great English botanist and explorer Joseph Dalton Hooker had advised the British government to leave all montane forests above 5000 ft. (ca. 1300 m) above sea level “undisturbed” and after 1873 the administration prohibited clearing and felling of forests throughout the central highlands. What a great idea that was! It is too bad there were not enlightened laws on hunting of wild animals as well. One Scottish officer in colonial service in Sri Lanka bragged he had shot and killed over 1400 elephants in Horton Plains and nearby. Today, there are none left there and, so far as we could determine, no plans to reintroduce them from the other remarkable parks, including Yalla and Uda Walawe….

So, what is the significance of the absence of elephants in this park? And, what else can we learn from past regimes and historic periods in Sri Lanka? For starters, we discover that conservation, and respect for other organisms goes back much further than the 19th century. Consider the sign at the entrance to Udawattakele Forest Reserve, near Kandy, one of the historic capitals from the long period of successive kingdoms the island had known prior to the European colonial chapter in Sri Lanka’s history:

“O Great King, the birds of the air and the beasts have an equal right to live and move about in any part of this land as thou. The land belongs to the peoples and the other beings and thou are only the guardian of it.”

-Arahath Mahinda (a son of the emperor Asoka the Great, who brought Buddhism to Sri Lanka)

How would it be if we could revive that approach to the Web of Life in our own day and age?

So, what has Horton Plains National Park, with its grassland-forest mosaic, its tourists, and its absent elephants got to do with the Central highlands of Madagascar? For one thing, we can see that fire is a big ecological driver in both areas. The abundant arborescent Rhododendrons in Horton Plains tell a vivid tale in this regard.

On the grand scale of things, Sri Lanka’s Central highlands also resemble those of Madagascar’s since both are the crowns of a poor, emerging tropical island with small and very similar human population size (21 million vs. 24 million), despite being much nearly ten times smaller, and with over 30,000 years of human history, as compared to merely two millennia for Madagascar.

Horton Plains also has remarkable conservation value both for its biodiversity and the ecosystem services it provides to people. Also, as I said, it’s a mosaic of grasslands and cloud forest, that in the past was certainly much affected by both elephants and fire.

Finally, both Sri Lanka (along with the Western Ghats of southern India) and Madagascar count among the world’s biodiversity hotspots, easily visible in their fauna and flora, which is one of the main reasons why MBG researchers, and many others travel and work in Madagascar.

Now, let’s turn back to fires. A big fire hit Horton Plains in 1998, and there are serious invasions of two noxious, cosmopolitan weeds, namely Gorse and Bracken fern. Some control work is underway on the Gorse, but the Bracken fern is apparently not seen as being a problem. Rainbow trout were introduced in the 19th c. and apparently have displaced all native fish, and are taking a toll on native shrimp and no doubt other fauna.

Gorse (Ulex europaeus) – a spiny invasive introduced as an ornamental in the colonial period for its pretty yellow flowers and now a noxious weed throughout the highlands of Sri Lanka.